Submerged water heating device



Jan. 15, 1935. JOHNSON' 1,987,855

SUBMERGED WATER HEATING DEVICE Filed Dec. 12, 1932 iIIIII A Patented Jan. 15, 1935 PATENT orrlce SUBMERGED WATER HEATING DEVICE Forrest A. Johnson, Chicago, Ill., assignor to Bell & Gossett Company, Chicago, Ill., a corporation of Illinois Application December 12, 1932, Serial No. 646,760 2 Claims. (01. 122-32) My present invention relates to improvements in submerged water heating devices.

I am aware that coils and loops of tubing, through which the water to be heated circulates, have been installed below the water line in steam boilers and within boilers for heating water for hot water premises heating. Such loops and coils have also been installed in casings exterior of the boiler through which the boiler water circulates.

My present invention refers more particularly to installations of heat transfer elements, through which the water to be heated circulates, within the boiler, and has for its principal object the increasing of the efiiciency of such heat transfer elements by means of increasing the circulation of the hot boiler water about and in the immediate vicinity of the heat transfer element.

I have attained the aforementioned object by means of the structures illustrated in the accompanying drawing, in which Fig. 1 is a fragmental front elevation of a boiler, a portion thereof being broken away to show the installation of my water heater therein.

Fig. 2 is an enlarged fragmental detail show- 25 ing a slightly modified closure plate for the aperture in the boiler through which my water heater is introduced with the water heater in assembly therewith.

Fig. 3 is a section on line 33 of Fig. 2.

Fig. 4 is a fragmental detail to an enlarged scale showing an assembly between the heat transfer coil and the closure plate for the boiler; and

Fig. 5 is a fragmental detail of the baffle and the tube for directing the gravitation of the cooled water therefrom.

Similar reference characters refer to similar parts throughout the several views.

For the installation of my invention an opening 5, sufficiently large to permit the introduction of the heater, is provided in the boiler casing of the boiler below the water line thereof and to close this opening is provided a closure plate 6 secured over the opening 5 by stud bolts 7 and nuts 8 in the usual manner for closing boiler openings. Bores or apertures 9, preferably one above the other, are provided in the plate 6, preferably on a taper, as shown in Fig. 4, for the passage of the ends of a hot water coil 10. The ends of the hot water coil are correspondingly tapered to fit the bores 9 and the portions of the ends of the coil 10 which extend beyond or outside of the plate 6 are interiorly and exteriorly threaded to receive the securing nut 11 and also to connect with the conduit leading to the hot water storage tank or other destination. About the coil 10 is provided a cylindrical baffle 12 secured to the plate 6 by spot welding, or in any other desired manner. The top and bottom edges of the baffle 12 are preferably flanged inwardly, as at 13 and 14, but these flanges are of such dimensions as to permit a free flow of the boiler water into the top and out of the bottom of the baflle 12. Usually, if not invariably, the cold water enters at the bottom of the coil 10 and the heated water discharges from the top of the coil 10. When heat transference commences at the bottom of the coil 10 the boiler water, which is cooled by such heat transference, gravitates or settles toward the bottom of the boiler drawing in a supply of heated water for replacement from the closest lateral and vertical positions. Also the chilled water falling or gravitating from the heat transfer element mixes with contiguous portions of the boiler water.

When the coil 10 is surrounded with my baflle 12, however, the hottest Water from the top of the boiler is drawn in at the top of the baffie by the gravitation of the chilled water from the bottom of the baffle and the gravitation of the chilled water from about the coil is prevented from mixing with the contiguous boiler water until it discharges from the lower end of the baflie, in which way a considerably enhanced circulation of the boiler water is induced in the immediate vicinity of the coil 10 which increases the efllciency of the coil 10 as a heat transfer element.

I have found that the efliciency as a heat transfer element of the coil 10 can be further enhanced by prolonging the baffle below the coil in certain cases, and to permit this and still be able to insert the bafile and the coil through the opening 5 in the boiler I employ a tube 15 having flanges 16 at its upper end which are of sufficiently small diameter to enter the coils of the coil 10 but are of sufficient size to engage with the lower flanges 14 upon the bottom of the baffle. After the balile and coil have been inserted in the boiler, tube 15 settles down to the position shown in Fig. 5. The effect of the tube 15 is to prevent the mixture of the cooled water with the boiler water until the cooled water is nearer to the bottom of the boiler, thereby somewhat increasing the hydrostatic head which causes the circulation through the baffle 12 and about the coil 10.

A good portion of the time necessary in heating the fluid contents of a vessel is caused by the interference between the hot water which is rising from the heating surfaces and the cold water which is settling to the heating surfaces. Insofar as the gravitation of the cooled water from about the coil 10 is concerned I have largely eliminated such interference.

Having described my invention what I claim as new and desire to secure by Letters Patent is:

1. A heat exchange element adapted for in-- stallation through a restricted opening of substantially the height of said element in a boiler wall in the boiler water of aboiler, and arbaflle surrounding said heat exchange element having openings in the top and bottom thereof, in? wardly extending flanges about the lower aperture in said baflle and a tube having lateral flanges at the top thereof co-operating with said lower opening.

2. A heat exchange element adapted for installation in the boiler water of a boiler adjacent the water level of said boiler water and a baffie surrounding said exchange element having openingsvadiacent the top andtbottomjthereof and extending below said exchange element to adjacent the bottom of the boiler water compartment of 10 said boiler.

' FORREST A. JOHNSON. 

